Electrical plug and socket structure



Dec- 27, 1938. T, w. wALl SICHLAEGEIR 2,141,889

ELECTRICAY PLUG AND SOCKET STRUCTURE Filed May 15; 1936 v I zz/ve 21/20:": Theodore Z Z'mer ia kllrcfilaeyel',

Patented Dec. 2 7, 1938 PATENT OFFICE.

ELECTRICAL PLUG AND socxn'r c'rmm STRU Theodore Werner Wallschlaeger, Chicago, 11]., as-

signor to Cinch Manufacturing Corporation,

Chicago, 11]., a corporation of Illinois Application May is, 1936, Serial No. 79,500

7 Claims. (01. 173-332) My invention relates to improvements in a plug or like device for an electrical plug and socket connection and towinstallations of the same.

'Referring'to the drawing, which illustrates a preferred embodiment of my invention:-

Figure 1 is a side elevation of my electrical. plug and socket installation;

Fig.2 is a bottom planview of the installation shown in Fig. 1 with a possible first position of my improved guide means shown in dotted lines;

Fig. 3 is a fragmentary section taken along the line 8-4 of'Flg. 2;

Fig. 4 is a section similar to that of Fig. 3 showing the plug member of my installation is withdrawn from electrical connection'with the socket member and in a position one hundred and eighty degrees rotated from the engaging position with the socket;

Fig. 5 is a top plan view ofthe attaching part of my plug member;

Fig. 6 is a bottom plan view of the'attaching part of my plug member; and

Fig. 7 is a top plan view of the socket member of the installation. An object of. my invention is to provide a simple, yet eflicient, means for guiding the prongs of a plug member. into correct position for connection with the proper cooperating prong-re ceiving elements of a socket member.

Other objects of my invention will beapparent from an inspection of the drawing in which Figs. 1 and 2 represent a plug member i having an attaching part 2 carrying contact prongs which are in engagement with contact elements 3 of a'socket member I. A guide means 5 extends through thesocket member 4 for reasons which will be hereinafter described.

Referring now in detail to.the plug member of the installation, I have shown in Figs. 1, 3

and 4 a well known connector plug member comprising a cup-shaped part 6, which may be made of sheet metal or any other suitable material, having. an open end to which is secured the attaching part of my plug member. The attaching part of my plug member, illustrated in Figs. 5 and 6, comprisesa lower insulating plate I carrying a plurality of contact prongs 8 adapted for contact with cooperating terminals of the socket member of my installation. The contact parallel relation one to another and are arranged in substantially circular relation within the outer periphery of the plate 1, as most clearly shown in Fig. 6. The relative length and transverse diameter of each of the prongs 8, in my preferred form,

prongs 8 preferably extend from the plate Lin ferred i'orm,-aportion l8 of the are substantially the same. A second insulating plate 9 is disposed above the plate 'l-with its peripheral outer edge, in my preferred form, disposed within the peripheral outer edgeof the plate I, as most clearly shown in Fig.6. The 5 plate 8 has a plurality of apertures I 0 in alignv ment with the contact prongs 8.

In order to prevent the prongs 8 from being engaged with the wrong contact terminals of the socket member when electrical connection is 10 made between the plug and socket members, I have provided a guide means 5 preferably made. of metal and formed in a manner to provide a substantially rectangular-shaped portion ll having opposed.- flat sides. The rectangular-shaped 13 portion Ii extends beneath the plate 1 in. the same direction; as the prongs 8 to a point below the outermostends of the prongs 8, as shown in Fig. 4. The portion II is disposed within the circle of the prongs 8 and has a pair of opposed longitudinal free edges in oil'set relation relative to the center of the circle (Figs. 4 and 6) for reasons which will be hereinafter more. fully' described. Shoulders l2 are formed-at one end of the rectangular portion of the guide means 5 25 engagingthe undersurface of the plate 1, and a shank i 3 extends upwardly between the shoulders 7 through the plates 1 and 9 in the manner shown in Figs. 3 and 4. The free end of the shank II is bifurcated so as to provide portions ll engaging the upper surface of the plate 8. As a result of this construction, the plates 1 and Sate maintained in secure assembly between the shoulders l2 of the guide means 5 and the bifurcated portion's ll. The opposite end of the rectangular portion II from the shank II, in my preferred form, is notched adjacent one longitudinal free edge so as to provide a shoulder l5 and an integral extending portion It of less width than that of the rectangular portion ll- (Figs. 3 and '4) In securing my attaching part to the open end of the cup-shaped container 8, portions ll 'of the material adjacent to the free end of the container are bent inwardly between the plates I and 8 so as to engage the undersurface off the 45 plate 9, as most clearly shown in Figs. 3 and 4. As a result of this constmction the insulating plate 3 is located within the cup-shaped conainer 6 andthe plate I is disposed adjacent to. ihe peripheral free edges of the container 8 and in close relation to the plate 8. In my prejacent to the free edge of the container 6 extends downwardly into a notch I! provided in the pcripheral free edge of the plate I for the purpose 65 (not shown) and a neck 20 large enough on the inside to allow the. entrance of a wire or group of wires into the container 6 for attachment to the prongs 2 carried by the plate I. In general, the cooperation between the two parts and the construction are the same, as best illustrated and described in United States letters Patent to Carl L. Knutson, No. 2,031,564, issued February The particular socket which I have chosen in my preferred installation has a relatively thin bottom plate 2| formed of insulating material having yieldable socket terminals arranged 'in substantially circular position about an aperture'. The aperture comprises a substantially circular hole 22 which is located in the center of the ring of terminals and has a notch 22 on one side extending toward the circle of elements. While yieldable contact terminals of any suitable construction may be associated with the bottom plate 2|, I have shown preferred contact members provided with-tubular prong-receiving portions 22 and integral soldering lugs 22 extending beneath the plate 2! for the usual purpose. The socket member is also provided with a top plate 22 of insulating material having apertures 21 (Fig. 7) arranged in alignment with the tubular prong-receiving terminals 24 to permit the e of the cooperating prongs of the plug member through the plate. 26 into engagement with the socket terminals. an aperture is provided within the ring of the apertures 21 'in alignment with the aperture within the ring of terminals 24 of the bottom plate 2| and shaped to provide a circular hole 28 which is located in the center of the ring of apertures and has a notch 22 on one side which extends toward the ring of apertures so that the aperture within the ring of them plate conforms in shape as nearly as possible with the aperture within the ring of the bottom plate. The plates '2i and 22 are secured together by the rivets and aligned apertures 2| are formed in the plates 2i andv 22 and adapted to receive a rivet or other means for attaching the socket member to a supporting part.

In moving my: plug member I into electrical connection with the socket member 2, the portion l2 at the free end of the guide means is inserted into the circular hole 22 located in the center of the ring of apertures of the top plate 22. When the portion Ii is first inserted into the hole, it is probable that the rectangular portion II will not align with the hole 22 and the notch 22 so that it may be passed completely therethrough, but instead will lie substantially across the hole 22 in the manner shown in dotted linesin Fig. 2. When the portion I6 is in this position, the shoulder it engages the material sur-. rounding the hole 22 and, as the width of the portion I2 is substantially equal to the diameter of the hole, it may be rotated therein 'until the shoulder i2 is in alignment with the notch 20, at which timethe rectangular-shaped portion ll of the guide means may be passed througlrthe top and bottom-plates of the socket member. As a result of my preferred construction, in

which one longitudinal edge of the recta s flrq shaped portion ii and the cooperatingnotch 22 of the, socket plate are oifset relative to the center of the circle of contact prongs 2 (Figs. 4 and 6) and the apertures 21 respectively, it is impossible to move the prongs into engagement with the cooperating prong-receiving portions 24 of the socket member unless the rectangularshaped portion II is passed throughthe centrally disposed apertures of the socket plates with the shoulder IS in proper alignment and relation with ranged to receive the prongs of the plug member. The portion ll can-only enter until the prongs 2 touch the socket. Thus it will be necessary for the operator to remove the portion II and start over until it is rotated to a position when it willenter the socket, as shown in Fig. 3.-

Although I have illustrated and described a preferred embodiment of my invention, I do not wish to be limited thereby because the scope of my invention is forth by the following claims. r

I claim: 3 1; An electrical binati'on, cooperatins plug and socket members, said plug member including a housing, a plurality of contact prongs extending from one end thereof and disposed in substantially circular relation, and a flat guide means disposed in off-center relation to the circle of said prongs, said guide means having one end secured withinsaid housing and the-other end extending in the same direction as said prongs said last mentioned end having a notch providing a shoulder, said socket having an elongated guide-receiving opening in certain positions of the plug relative to the socket,

connection comprising, in comsaid guide means adapted to extend completely through a cooperating aperture of a socket device only when said contact prongs 'are in registry with the proper prong-receiving elements of said socket device. i

2. An electrical connection comprising, incombination, cooperating plug and socket members, said plug member including a housing, a plurality of contact prongsextending from one end thereof,

and a guide means extending from said last-' mentioned end of said housing in the direction of said-prongs, said guide means having a notch at its free. end providing a shoulder, said socket having an elongated guide-receiving opening so that said'shoulder'.will rest against an edge of the opening in certain positions of the plug rela-' tive to the socket, said guide means adapted to extend completely through a cooperating aperture 01 a socket device only when said contact prongs are in registry with the proper prong-receiving elements of said socket device.

3. A' plug for electrical connections including a container having an open end, a plurality oi insulating plates in fixed assembly with said container-at saidopen end, a plurality of contactprongs carried by atleast one of said plates and;

toapointbeneathsaidprongs'Jaidbodyportion 12 ried by at leastone' of said means secured to said plates and extending there-. 'from in the direction of said prongs for cooper- 2,14r,ssa

tion extending through at least one of said plates, said shank having a bifurcated portion engaging the inner surface of said plate whereby said body portion is secured thereto, and said body portion having a notch at the other endpresenting a shoulder for the purpose described.

4.,A plug for electrical connections including a container having an open end, apair of insulating plates in fixed assembly with said container at said open end, a plurality of,contact prongs carried by at least one of said plates and arranged in substantially circular. relation, and a one-piece guide means carried by atleast one of said plates and disposed within the circle of said prongs and in oil-center relation thereto, one end of said guide means having portions in fastened engagement with at least one of said plates whereby said guide is secured thereto, the other end of said guide extending from said plate in the direction of said prongs and adapted to extend completely through a cooperating aperture of a socket device only when each of said contact prongs is in registry with the proper prong-receiving element of said socket device, said other end having a notch adjacent'one longitudinal'free edge of the guide providing a shoulder and an extending portion for the purpose described.

5. 'A plug for electrical connections including a container having an open end, a pair'of insulating plates assembled with said container at said open end, one of said plates secured within said container, the other of said plates located outside said container and in close relation to said first plate, a plurality 01' contact prongs carplates, and a guide ating with a socket device in a way to insure registration or each of said prongs with the proper prong-receiving terminal of said socket device, said guide having means engaging a surin the same direction face of said outside plate and a surface 01' said other plate for securing said outside plate to the other of said plates.

6. An electrical connection comprising, in combination, plug and socket members, said plug member having a plurality oi. contact prongs dis posed in substantially circular relation and extending from one end thereof, and a flat guide means disposed in oil-center relation to the circle 01 said prongs, said guide means extending in the same direction as said prongs, and said socket member carrying a plurality of prong-receiving terminals disposed in substantially circular relation, said socket member providing an aperture having an. elongation on one side disposed in oncenter relation to the circle of said wire-receiving terminals, said guide means extending through said aperture and said elongation only when each I .of said contact prongs is in proper registry relative to said respective prong-receiving terminal.

7 An electrical connection comprising, in combination, plug and socket members, said plug member having a plurality oicontact prongs disposed in substantially circular relation and extending from one end thereof, and a flat guide means disposed in ofl-center relation to the. circle of said prongs, said guide means extending as said prongs, and said socket member carrying a plurality '0! prongreceiving terminals disposed in substantially circular relation, said socket member providing an aperture having an elongation on one side disposed in off-center relation to the circle of said wire-receiving terminals, said guide means extending through said aperture and said elongation only when each ,of said contact prongs is in proper registry relative to said respective prongreceiving terminal, and said guide means having a notch at its free end adjacent to one longitudinal edge thereof providing a shoulder and an extension of said guide means permitting'relative rotation of the parts bei'ore proper registry. THEODORE WERNER WLI8CHLAEGER 

